861731 has 6 divisors (see below), whose sum is σ = 933300. Its totient is φ = 795288.

The previous prime is 861719. The next prime is 861733. The reversal of 861731 is 137168.

It is not a de Polignac number, because 861731 - 2¹⁴ = 845347 is a prime.

It is a super-2 number, since 2×861731² = 1485160632722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 861731.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861731.

It is not an unprimeable number, because it can be changed into a prime (861733) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2381 + ... + 2718.

It is an arithmetic number, because the mean of its divisors is an integer number (155550).

2⁸⁶¹⁷³¹ is an apocalyptic number.

861731 is a deficient number, since it is larger than the sum of its proper divisors (71569).

861731 is a wasteful number, since it uses less digits than its factorization.

861731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5125 (or 5112 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 861731 is about 928.2946730430. The cubic root of 861731 is about 95.1606147252.

Adding to 861731 its reverse (137168), we get a palindrome (998899).

The spelling of 861731 in words is "eight hundred sixty-one thousand, seven hundred thirty-one".